ZIF-67-Derived Co₃O₄ with Dynamic Active Sites Enabling SrTiO₃ for Efficient Photocatalytic Overall Water Splitting

Developing efficient and stable non-noble metal cocatalysts represents a promising yet challenging frontier in the field of photocatalytic water splitting. Herein, ZIF-67 derived Co 3 O 4 nitrogen doped graphitic carbon (Co 3 O 4 NGC) is uniformly deposited onto the surface of Al-doped SrTiO 3 (STO) via an in situ growth combined with a heat treatment method. The prepared Co 3 O 4 NGC/STO exhibits excellent activity for photocatalytic overall water splitting with stoichiometric H 2 and O 2 evolution, and the highest H 2 evolution rate reaches 1099 μmol h –1 g –1 with an apparent quantum yield of 9.27% at 365 nm, which is even higher than that of Pt loaded STO. In situ X-ray photoelectron spectroscopy accompanied by comprehensive characterizations demonstrate that the photogenerated electrons and holes respectively accumulate at Co 3 O 4 NGC and STO as driven by interfacial electric field, and Co 3 O 4 NGC containing Co 3+ /Co 2+ redox couples acts as dynamic active sites to significantly reduce the energy barrier for water splitting.